The present invention relates to a mobile enclosure unit for use in collecting airborne debris and contaminants inside a building while carrying out construction or repair work on or within a ceiling.
When conducting necessary construction and repair work inside a building, it is often necessary to restrict debris and airborne contaminants from falling onto the ground or entering the air in the surrounding space. This is particularly true when such work is carried out in a hospital, clinic, laboratory, or other sensitive or critical area, and when the work will create potentially hazardous dust or debris, such as asbestos dust.
U.S. Pat. No. 4,682,448 of Healey describes a shelter which defines an enclosure of rectangular cross-section extending from the floor to the ceiling, and having a top opening for access to a ceiling so that a worker in the shelter can carry out work on the ceiling without releasing contaminants into the area surrounding the shelter. The worker places a stepladder within the enclosure for access to the ceiling. An external vacuum apparatus is connected to the enclosure via a vacuum hose extending through an opening in the enclosure.
This shelter is still subject to various disadvantages, and does not necessarily exclude all debris generated within the shelter from entering the surrounding space. Use of a stepladder within the enclosure is awkward and inconvenient, particularly with varying ceiling heights. The external vacuum apparatus requires access through an opening in the enclosure, and this can cause leakage of contaminants if not properly sealed.
It is an object of the present invention to provide a new and improved mobile enclosure unit for protecting the surrounding environment from contaminants when performing construction or repair work on or within a ceiling within a building.
According to the present invention, a mobile enclosure unit is provided, which comprises a vertical, wheeled frame of generally rectangular cross-section having an open upper end and a closed lower end, the frame being adjustable in height so that the open upper end can be positioned in contact with a ceiling, a working platform adjustably mounted in the frame and movable to a selected height in the frame, the frame having a lower wall, a pliable cover sleeve surrounding the frame to form a chamber within the frame having an open upper end to allow a worker standing on the working platform to access a ceiling area above the open end of the frame, the sleeve extending from the lower wall to the upper end of the frame, and an exhaust system mounted in the frame inside the sleeve for drawing in air from the chamber, filtering debris from the air, and exhausting filtered air from the chamber to create a negative air pressure.
Preferably, the exhaust system includes an intake passageway having an intake opening adjacent the upper end of the frame and an outlet end, a filter unit connected to the outlet end of the intake passageway, and a suction unit such as a fan or vacuum pump connected to the filter unit for drawing air from the chamber through the intake passageway and filter unit, the suction unit having an outlet for exhaust of filtered air out of the enclosure. Preferably, the filter unit, suction unit, and exhaust outlet are provided on the lower wall of the frame. The filter unit is preferably a HEPA filter.
The open upper end of the frame is preferably adjustable in width to expose a smaller or greater ceiling area above the frame. The sleeve forms side walls of the enclosure and is preferably of a pliable fabric or plastic material, and is of sufficient height to extend from the upper end to the lower end of the frame when it is extended to its maximum height. The sleeve has an open upper end suitably secured to the open upper end of the frame, with the upper end being of width equal to the maximum width of the upper end of the frame when fully extended.
Both the frame and the sleeve are preferably of rectangular horizontal cross-section, having four perpendicular side walls. Preferably, the side walls of the sleeve are formed as separate panels which are releasably secured together by suitable fasteners such as zippers. An access opening into the chamber is provided by a cut out portion in one of the panels forming a door, with the cut out portion releasably securable to the remainder of the panel by a suitable releasable fastener such as a zipper.
A seal device is preferably provided around the open upper end of the frame and sleeve, to form a seal against a ceiling when the frame is extended to ceiling height. The seal may be of compressible rubber, foam material, or the like.
The enclosure unit of this invention can be readily positioned beneath a ceiling area where maintenance or the like is to be carried out. The frame is then extended until the seal device around the upper end is pressed against the ceiling around the area where work is to be carried out. The working platform is positioned at a suitable height, and, after entering the chamber within the outer sleeve, the worker closes and seals the entry opening. The exhaust system is then turned on. While work is carried out, any dust or debris created will be pulled downwards into the enclosure. Any airborne contaminants will be pulled in to the intake passageway and filtered out before exhausting the cleaned and filtered air back into the surrounding environment.
Preferably, a HEPA vacuum attachment is provided in the sleeve to allow the hose of a HEPA vacuum unit to extend into the chamber, where it can be used to vacuum off any debris that is attached to the frame, working platform, or to the worker""s clothing. Thus, the worker can vacuum off any debris before leaving the unit, further reducing the risk of introducing contaminants into the surrounding environment.
The mobile enclosure unit of this invention provides a convenient chamber for providing workers with access to a ceiling area while containing debris produced by the work. The unit includes a filtering system for filtering out any airborne debris produced by the workers, as well as a vacuum attachment to allow other debris attached to the unit or to the worker""s clothing to be cleaned up before opening and exiting the chamber. This significantly reduces or eliminates the risk of contaminating areas surrounding a site where ceiling construction or maintenance is being carried out.